JPH04123852A - Continuous caster for dividing width - Google Patents

Abstract

PURPOSE:To eliminate the problem on quality without exposing a segregating part even if the drawing down part is cut by arranging rolling reduction rolls for drawing down at a prescribed position in width direction of a slab at the prescribed position of the cast slab before completing the solidification and setting a cutting device for cutting the drawing down position in the longitudinal direction of the slab. CONSTITUTION:In multi-continuous rolling device 2 for guiding the cast slab drawn from a casting mold 1 in a continuous caster, the rolling reduction rolls WR for drawing down only the prescribed position in the width direction of slab 5 are arranged at the prescribed position 9 in the range guiding the cast slab 5 before completing the solidification, and the cutting device 4 for cutting the drawing down position in the longitudinal direction of slab, is set with the rolling reduction roll WR at the outlet side of multi-continuous rolling device 2.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a continuous casting machine for width division.

[Prior art] In order to manufacture narrow slabs with good productivity in a continuous casting machine, generally a wide slab is cast and then vertically cut using a longitudinal cutting device outside the continuous casting machine. This method exposes center segregation on the cut surface, which poses a problem in terms of steel quality. In particular, cracks occur during rolling of H-beam steel and the like. Additionally, surface flaws generally remain on the product and require various surface care processes. As a means of alleviating the problem of the centrally segregated exposed portion, there is a technique introduced in Japanese Patent Publication No. 4]-2] 324 of the 1970s.

This technology involves casting a slab with longitudinal grooves into a casting mold, forming the grooves of the slab with grooves after exiting the mold into deeper grooves using a grooved roll, and then rounding the deep grooves. It is cut with a saw.

[Problems to be Solved by the Invention] In the above-mentioned grooved slab manufacturing technology, the casting mold is provided with protruding protrusions on the inner wall for groove grooves, so that the cooling effect of the protrusions is greater than that of other parts. Unfortunately, cracks such as vertical cracks frequently occur in the solidified shell within the mold. In addition, in the secondary cooling zone after leaving the casting mold, cooling water collects in the grooves and flows or accumulates, making it impossible to obtain a uniform cooling effect, resulting in cooling spots and frequent surface cracks. Furthermore, when deep grooves are formed, stress concentration in the grooves causes severe internal cracks or surface cracks, which significantly deteriorates the quality of the slab.

The present invention uses a normal mold with a flat inner wall surface to cast a wide slab that does not cause internal cracks or surface cracks, and at the same time, during the solidification process of this wide slab, center segregation is generated in the area where vertical cutting is planned. This was done in an attempt to eliminate it altogether.

[Means for Solving the Problems] A feature of the present invention is that a cast slab before solidification is processed in a multi-continuous roll device that guides a cast slab coming out of a casting mold of a continuous casting machine that manufactures slabs. A reduction roll for rolling down only a predetermined position in the width direction of the slab is provided at a predetermined position in the guiding area, and a slab longitudinal cutting device for cutting the rolled position by the reduction roll is provided on the exit side of the multi-continuous roll device. A continuous casting device for width division is characterized by the following:

In the present invention, the roll-down roll may be a short-axis roll that rolls down only the cut portion in the longitudinal direction of the slab, as in the embodiment.

Also, as a long shaft roll, the diameter increasing part is fixed or rotatably supported at a predetermined position on the roll body, or
The diameter-increasing part may be screwed together to be movable in the roll axis direction, or the roll itself may be movable in the roll-axis direction, so that the rolling position by the diameter-increasing part can be set at any position in the slab width direction. Further, the reduction roll may be installed on one or both of the width surfaces of the slab. The rolling down roll with the roughly increased diameter portion may be installed so that it can be moved up and down, the rolling force can be adjusted, etc. as necessary.

The shape of the rolling surface of the rolling roll may be curved, chevron-shaped, polygonal, flat, or any other suitable shape.

In addition, in the case of a rolling roll with a fixed rolling position, move one or both of the short pieces of the mold to change the width size and axis of the slab so that the vertical cutting position matches the rolling position of the rolling roll. You can.

[Function] The present invention uses the reduction roll to reduce a predetermined vertical cutting position of the slab before completion of solidification, thereby reducing the unsolidified portion to zero and discharging the concentrated components to the unsolidified portion of the non-rolled portion. By bonding or reducing the thickness by 10-30+ nm to make it thinner than other parts, solidification is completed before the uncompressed part, and solidification of concentrated components is avoided. As a result, even when the rolled part is cut, the segregated part of the concentrated component is not exposed on the cut surface, and all of the above-mentioned quality problems are advantageously solved.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

This embodiment is applied to a curved continuous casting apparatus.

In Figure 1, LD is a ladle, TD is a tundish,
ST is a swing tower that supports and rotates the ladle, 1
2 is a mold having a movable pair of long pieces and short pieces each having a flat casting surface; 2 is a multi-continuous roll device; 3 is a straightening roll provided at the boundary between the curved portion and the horizontal portion; 4 is a multi-continuous roll device 2 Gas cutter for vertical slab cutting installed on the exit side of the
0 is a cutter for cutting across the slab, 11 is a dummy bar,
12 is a device for separating the tummy bar and the cast slab 5; The reduction roll is installed in a stand 9 provided 1.5 m upstream from the solidification completion point 6 of the cast slab 5 in the horizontal section, as shown in FIG.

In Fig. 2, the cast slab 5 has a width of 1900 mm and a thickness of 2.
80 mm, 6 indicates the solidified point of the cast slab 5, 7 indicates the solidified shell of the cast slab 5, and 8 indicates the unsolidified portion of the cast slab 5. The thickness of the unsolidified portion 8 of the slab 5 at the position where the reduction roll R is arranged is 70 mm.

As shown in FIGS. 2 to 4, the stand 9 includes a pair of upper and lower beams H, 11□ and connection support columns S1 to S4, which also have a roll gap adjustment function for connection, and are arranged at the top and bottom of the front and rear ends. The full-width guide roll GR1 is composed of divided kite rolls sn disposed above and below the center to the left and right, and roll-down rolls WR disposed above and below the center and each having a roll-down mechanism.

The reduction roll WR forms a convex curved surface on the reduction surface, and reduces the vertical cutting position of the cast slab 5 by 5 mm above and below, respectively, thereby reducing the thickness of the unsolidified portion 8 from 70 mm to 60 ml'l. As a result, the pressure-F portion completes solidification earlier than the other portions, thereby avoiding the formation of a segregated portion of concentrated components.

Fig. 5 shows another example of a stand incorporating a pressure F-roll, including a guide roll GR and a segment stand ST.
The roll-down roll WR2, which is installed between the upper and lower rolls and shows the arrangement of the lower rolls, is pivotally supported on a sliding shift cart SS in the slab width direction, and is moved by an electric motor M to a spline shaft joint F.
Rotation drive through. US indicates a hydraulic cylinder for driving the truck.

[Effects of the Invention] As is clear from the above explanation, the present invention uses the reduction roll to reduce a predetermined vertical cutting position of the slab before solidification is completed, and converts the unsolidified portion into cellulose to release the concentrated component. It is excluded and joined to the unsolidified part of the unrolled part, or the thickness is reduced by about 10 to 30 mm to make it thinner than other parts, so that the solidification is completed before the unrolled part and the solidification of the concentrated component is avoided. As a result, even when the rolled part is cut, the segregated part of the concentrated component is not exposed on the bright cross section, which advantageously eliminates all of the above quality problems.
The effects contributing to industry are enormous.

[Brief explanation of drawings]

FIG. 1 is a bird's-eye diagram showing the whole of one embodiment of the present invention, and FIG.
The figure shows a stand incorporating a reduction roll, which is a main part of this embodiment, and a side sectional view taken from arrow A-A in FIG.
The figure is a front sectional view taken along the line BB in FIG. 2, and FIG. 4 is a plan sectional view taken along the line CC in FIG. 3. FIG. 5 is an explanatory plan view showing another example of a stand incorporating reduction rolls, showing only the lower roll arrangement among the upper and lower rolls. LD...Ladle, 'rD...Tandish, ST.
・・Swing tower, H,, H2 ・・Beam, S1~S4
...Support column, GR...Full width guide roll, SR...
・Divided guide roll, Wll...reduction roll, 1...
・Mold, 2... Multi-continuous roll device, 3... Straightening roll, 4... Gas cutter for vertical slab cutting 5... Slab slab, 6... Solidification completion point, 7... Solidified shell , 8
... Unsolidified part, 9... Stand, 10... Slab cross cutter, 11... Dummy bar, 12...
・Disconnection device ``-''.

Claims (1)

[Claims] 1. In a multi-continuous roll device that guides a cast slab that has come out of a casting mold of a continuous casting machine that manufactures slabs, at a predetermined position in the area that guides the cast slab before solidification is completed,
A roll-down roll that rolls down only a predetermined position in the width direction of the slab is provided, and a slab longitudinal cutting device that cuts the rolled-down position by the roll-down roll is installed on the exit side of the multi-continuous roll device. Continuous casting equipment for division.